Portable electronic devices, such as digital audio players, mobile telephones, and the like, have become increasingly popular. These devices generally require a user to hold the device to their ear either directly or indirectly by way of earphones or a headset. Although these devices perform well for a single user, users sometimes find that amplifying the sound for either multiple listeners or for “hands-free” use is desired.
Radio transmitters transmit audio signals from a device, such as a portable electronic device, to be detected by a remote radio receiver. In general, a transmitter is programmed to be switched between a few pre-determined channels, the user selecting one of the channels for transmitting the audio signals. The use of a transmitter may require a user to manually locate the available channels on a radio band to determine which channel is sufficiently quiet for transmitting the audio signals. The user generally determines which of the channels is quiet simply by listening directly to the quality of signals on the available channels. Once the user has identified a quiet spot, the user may need to switch the transmitter to the selected channel and enable the electronic device. After starting up or enabling the electronic device, the user then may be able to transmit audio signals from the device to the remote radio receiver.
In some cases, a quiet spot on a radio band may become non-quiet. Sometimes this may be due to movement of the remote radio receiver, which may cause a quiet spot to become closer to a location of a transmitter of a radio station which broadcasts on the particular frequency of the selected quiet spot. For example, a user may use a transmitter in a vehicle to play music from a digital audio player. While driving, the music may be interrupted by a radio station broadcasting on the same frequency of the quiet spot. This may be due to the radio station's signal becoming stronger as the user has driven closer to the source of the radio station's signal. Resultantly, the user must repeat the process for finding another quiet spot. In some larger urban areas, the user may encounter extreme difficulties in locating and/or maintaining a quiet spot. In addition to the possible dangers of requiring the user to repeatedly locate quiet spots while driving, frustration may lead the user to forego use of the transmitter altogether.